Pontoon dry-dock.



H. A. GRAY.

PONTOON DRY DOCK.

APPLICATION PuiMun/18.1918.

[1,300,954. Patented Apr.15,1919.

2 SHEETS-SHEET l.

H. A. GRAY.

PoNooN DRY DOCK.

APPLICATION FILED JULY1B,19IB.

1300954 Patented Apr. 15, 1919 I y 2 SHEETS-SHEET 2.

ern f v 'HOWARD A. GRAY, 0F GODFREY, ILLINOIS.

roix'rrooN DRY-DOCK.

Specification of Lettersv Patent.

Patented Apr. 15,1919.

' Application mea July 1s, 191s. serial No. Y(245,519.6.

T0 all whom t may concern.'

Be it known that I, HOWARD A.v GRAY, a citizen ofthe United States,residing at Godfrey,'in the county of Madison and State `of Illinois,have invented certain new and useful Improvements in Pontoon Dry-Docks;and I do hereby declare the following to be a full, clear, and eXactdescription of the invention, such as will enable others skilled in theart to which it appertains to make and use the same, reference being hadto the accompanying drawings, and to the letters and figures ofreference marked thereon, which form a part of this specification.

This invention relates to new and useful improvements in submersibleiioating dry docks especially adapted for receiving salvaged vesselswhich have been raised from the bottom of the sea, and consistsV of asimple and eioient device of this nature having various details ofconstruction, combinations and arrangements of parts which will behereinafter fully described, shown in the accompanying drawings and thenspecically defined in the appended claims.

I illustrate my invention in the accompanying drawings which, with theletters of reference marked thereon, form a part of this application andin which:

Figure 1 is a top plan view.

Fig. 2 is a sectional view on line 2-2 ofy Fig. 1.-

Fig. 3 is a longitudinal sectional view through the compartments of thedock, and

Fig. 4 is a 'detail view of a chain gear wheel.

Reference now being had to the details of the drawings by numerals;

1 designates a floating dry dock provided with individual compartments2, having iood valves 3 and centrifugal pumps 4, one provided for eachcompartment of the pontoon and provided for the purpose of'permittingthe dry dock to maintain its level while the vessel is being drawn intothe same and allowing the bow end of the dock to be ballasted, whilewater may be pumped out of the stern of the compartment, making thestern buoyant as the vessel is being drawn into the'dock.

A chain gear 5 is mounted near the forward end of the dock and overwhich cables 6 for drawing the vessel into the dock are adapted to run.Said chain gear 5, a detail of which is shown in Fig. 4 of the drawings,consists merely of a sheave with recesses or indentures 5 formedtherein, in orderv to grip the lengths of the chain andl is used"instead of a drum, as it would be inconvenient to wind up a considerableamount of heavy cable chain, but by the employment of a chain gear, theslack passes down through the hole in the deck of the dry dock and maybe conveniently let out when desired by a reverse movement of the chaingear. Suitable gates 8 are provided at the stern of the dock, wherebythe same may be opened when it is desired to permit the ship to passinto or out of the dock. Anti-friction rollers 10 are journaled atintervals on the opposite sides and on the bottom of the dock, andagainst which the vessel is adapted to contact as it enters or leavesthe dock. A retarding cable 11 passes over pulleys 12 and winds about achain gearvl, similar to the gear 5, and which is fixed to a suitableshaft 16 having a beveled pinion gear 17 meshing with a pinion 18`rotated with a motor shaft 19, said motor contained within the casing20. A beveled gear 21, Xed to the shaft 19 meshes with a gear 22 keyedto the shaft 23, and which latter has a beveled gear 24 in mesh with thepinion 25, which drives the stub shaft 5X to which the chain gear 5 iskeyed.

It will be noted that the motor drives two similarly constructed andoperated chain gears 15, one upon either side of the motor. It will benoted upon reference to the drawings that the bow of the vessel comingin contact with the horizontally disposed portion of the cable, willcause the latter to be moved forward and passing over chain gears willtend to act as a brake mechanism, permitting the vessel to enter thedock slowly.

It will be understood that my dry dock is adapted to be submerged, inorder to receive an entirely submerged hull of a vessel, and when oncewithin the dock the gates may be closed and the dock rendered buoyant bypumping out the water within the same and also the water within thevessel in the dock.

By the provision of the pumps in the various compartments and the floodvalves, the dock may be held at different inclinations to facilitate thedocking of the vessel and righted to horizontal position by expellingwater from one or the other of said compartments, by pumps adapted tooperate independently or simultaneously.

What I claim to be new is:

1. A submersible dry dock having gates at yenters the dock.

2. A submersible dry doek having gates atone. end thereof, a cablepositioned Vagainstone end thereof, 'y a yielding cable against which aboat entering the dock is' adapted to Voontact, and means connected. tothecable regulating the movement of the boat as it the entrance into thedock and against which the prow of the boat is adaptedv to contact, andpower, mechanism connected'to the cable.

v V3. submersible dry dock having gates at Y `Copies of this patent maybeobtaine for cable adapted to be 'disposed in the path of 15 :the-boatas it enters the dock.

signature in presence of two witnesses.

y Witnesses: y

I. J. BEARD, n

IfALMsGm ve cents each, by addressing'the Commissioner of Patents." lWashington, D. C.

In testimony whereof I hereunto affix -my' HOWARD A. GRAY. Y

